Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
  • C07D307/77—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom ortho- or peri-condensed with carbocyclic rings or ring systems
  • C07D307/87—Benzo [c] furans; Hydrogenated benzo [c] furans

Definitions

• This invention relates to fungicidal materials and more particularly to 4,5,6,7 tetrachloro-4,7-endoxo-4,7,8,9- tetrahydrophthalane derivatives having fungicidal activity.
• the product of the Diels Alder synthesis is accordingly a mixture of compounds. It has been proposed previously to treat a mixture of the endo-and-exo forms of 4,5,6,7- tetrachloro-4,7-endoxo-4,7,8,9-tetrahydrophthalane with about 30-39% hydrochloric acid at elevated temperatures and elevated pressures whereby the mixture of the endoand-exo-forms of 4,5,6,7-tetrachloro-4,7-endoxo-4,'7,8,9- tetrahydrophthalane is converted into 4,5,6-trichioro-7-hydroxy-phthalane in good yields.
• the 4,5,6-trichloro-7- hydroxy-phthalane is characterized by an exceptionally high fungicidal activity and is extremely valuable for use in inhibiting or fully suppressing the growth of many fungi.
• a disadvantage of the hydrochloric acid treatment process is that the reaction product which is thereby obtained contains a small amount of dark colored by-products, which must be separated in a subsequent purification step.
• the hydrochloric acid treatment has further disadvantages, it can only be performed in hydrochloric acid resistant pressure vessels which have, for instance, been constructed with glass, enamel, tantalum, or Teflon-linings.
• This invention has as an object a simple and practical method for production of fungicidal materials from mixtures of the endo-and exo-forms of 4,5,6,7-tetrachloro- 4,7-endoxo-4,7,8,9-tetrahydrophthalane avoiding the disadvantages of the heretofore available methods.
• a further object is a method for the preparation of 4,5,6 trichloro 7 hydroxy-phthalane, 5,6-dichloro-8,9- dihydrophthalochinones (4,7) and 5,6-dichloro-4,7-dih'- droxyphthalane.
• a still further object is at method of treating a mixture endow-4,7,8,9-tetrahydrophthalane to produce 4,5,6-trichloro-7-hydroxy-phthalane, 5,6-dich-loro-8,9 dihydrophthalochinon (4,7) and 5,6-dichloro-4,7-dihydroxyphthalane.
• the solid reaction product need not necessarily be separated into its separate components following the sulfuric acid treatment but can be used per se or after a conventional formulation as a fungicide.
• the conversion is expediently carried out by dissolvting thestarting mixture in'90 to 98% sulfuric acid with stirringat a temperature of from l5 to 35 C. for several hours. No hydrochloric evolution is thereby observedbut only a' homogenization of the reactants.
• the homogeneous reaction solution is diluted by addition of ice thereto.
• the sulfuric acid solution is extracted with ether'at a temperature of less than about C., the ether extract neutralized with sodium bicarbonate solution, dried over calcined sodium sulfate, filtrated and concentrated.
• the oil which is so obtained is unstable and is converted during the standing at ambient temperature into a white solid substance. Because of the geminal arrangement of the hydroxyl group and the halogen atom on the same C-atom in both the 4- and 7-positions, the intermediary product stabilizes with liberation of 1 mol of water and 1 mol of hydrochloric acid under aromatization in quantitative reaction to 4,5,6-trichloro-7-hydroxyphthalane.
• reaction takes place according to the following reaction scheme in which the two stereoisomeric forms of the starting material are represented by a single projection formula:
• 4,5,6,7-tetrachloro-4,-7-dihydroxy 4,7,8,9 tetrahydrophthalane is dissolved 'in the organic solvent (as obtained in the extracting' of the sulfuric acid solution with ether).
• 4,5,6-trichloro-7-hydroxy-phthalane can be ob tained by evaporation from the ethereal solution after the same has been-permitted to stand at ambient temperature for l2'to 24 hours.
• EXAMPLE 1 60.0 g. of a pulverized mixture of the endo and the exodrophthalane were added to 600 ml. sulfuric acid at ambient temperature. A slight increase in temperature was observed along with an instantaneously and violent evolution of hydrochloric acid. After termination of the reaction, the yellowish brown contents of the flask were poured onto crushed ice. The resulting crystalline solid was filtered off, washed with water and dried, yielding- 48.0 g. of a raw product having a fungicidal activity.
• EXAMPLE 2 50 ml. 98% sulfuric acid were added at 5 C to 10.0 g. of 4,5,6,7-tetrachloro-4,7-endoxo-4,7,8,9-tetrahydrophthalanes containedin-anopen-vessehand the resultant reaction mixture was thoroughly stirred. After appoximately half an hour, the phthalane was dissolved. Thereafter, crushed ice wasadded to the reaction mixture and a yellow solid resulted which was filtered off and taken up in ether. Following neutralization and dr ing, the solution was evaporated. 7.8 g. of a crystallizate were obtained which, after redissolution in ethyl acetate produced 7.0 g. of 4,5,6-trichloro-7-hydroxyphthalane having a melting point of 227:5 to 228 C. During the dissolution, HCl was evolved.
• EXAMPLE 3 10.0 g. 4,5,6,7-tet1rachloro-4,7-endoxo-4,7,8,9 tetrahydrophthalane were treated with 100 ml. 98% sulfuricacid for approximately one minute at 20 to 30 (land thereafter diluted with crushed ice. The reaction mixture so obtained was extracted with ether, the extract twice washed with water and dried over calcined sodium sulfate. 1.5 g. of 5,6:dichloro-8,9 dihydrophthalochinone- (4,7) precipitated from the ethereal solution which had been concentrated but not fully evaporated to dryness. From the residual mother liquor 6.2 g. of 4,5,6-trichloro- 7-hydroxy-pht-halane was recovered.
• EXAMPLE 4 10.0 g. 4,5,6,7-tetrachloro-4,7-endoxo-4,7,8,9-tetrahydrophthalane were treated with 100 ml. 98% sulfuric acid at 20 .to 30 C. in an open vessel. After stirringfor 5 minutes, crushed ice was added to the reaction mixture. The precipitate formed was separated from the liquor by suction and washedsulfuric acid free with water. There were recovered 7.0 g. of a solid from which 2.0 g. of 5,6- dichloro-4,7-dihydroxy-phthalane-hydrate were recovered by extraction thereof with hot water.
• the 5,-dichloro-4,7-dihydroxy-phthalane was reacted with phenyl isocyanate to form the bis-phenylurethane melting at 230 to 231.5 C.
• EXAMPLE 5 i ed 17.3 g. of a crystalline substance having a melting range of 160 to 200 C. and consisting essentially of a mixture of 4,5,6-trichloro-7-hydroxy-phthalane and 5,6-dichioro-4,7-d-ihydroxy-phthalane. Both substances were separated by fractional. crystallization and identified specifically as 4,5,6trichloro-7-hydr0xy-phthalane and 5,6-dichloro-4,7-dihydroxyhthalane.
• EXAM?LE 7 27.6 g. (0.10 mol) of a finely pulverized mixture of the endo-and the exo-form of 4,5,6,7-tetrachloro-4,7-endoxo- 4,7,8,9-tetrahydrophthalane were added to 100 ml. 98% sulfuric acid contained in an open 250 ml. Erlenmeyeflask under stirring using a magnetic stirrer. The acid was kept at -20 to 25 C. by means of an ethyl alcohol carbon dioxide refrigerating bath. After approximately 1 hour, the solid substance added to the sulfuric acid was dissolved and a colorless, homogeneous solution formed.
• the fungicidal activity of the product comprising 4,5,6,6-trichloro-7-hydroxyphthalane (I), 5,6-dichloro- 8,9-dihydrophthalochinone-(4,7) (II) and 5,6-dichloro- 4,7-dihydroxy-phthalane (III) prepared in accordance with the invention is shown in Table I, that of the novel compounds 11 and III of the invention in Tables II to V.
• the fungicidal eifect of the product as a whole, as well as of the individual compounds II and III respectively was determined according to the standard test of the American Phytopathological Society (Fhytopathology, vol. 33, p. 627 to 632 (1943) and v01. 37, p. 354 to 356 (1947));
• the numbers as set out represent the percentage of ungerrninated spores counted.
• the product as a whole or thenovel compounds 5,6- dichloro 8,9 dihydrophthalochinone-(4,7) (H) and 5,6 dichloro-4;7-dihydroxy-phthalane (III) may be used in the conventional manner for preparing fungicidal compositions, namely by incorporating a fungicidal effective quantityv thereof in liquid or solid diluents wellknown in the art; Thus for example, they may be formed into a afungioidal spray by dissolving or dispersing in the conventional liquid carrier materials for fungicides, eventually with addition of commercially available emulsifiers, dispersants; detergents or adhesives, further they may befbrmedintoan aerosol in the conventional manner or into dusting powder by admixture with a commercially available inert solid carrier material.
• Process for the production of a'fungicidally active derivative of 4,5,6,7-tetrachloro-4,7-endoxo-4,7,8,9 tetrahydrophthalane which comprises contacting a mixture of the endoand ex'o-forms of 4,5,6,7-tetrachloro-4fl-endoxo-4,7,8,9-tetrahydrophthalane with 70-98% sulfuric acid at a temperature of below --10 C., isolating from the resulting homogeneous solution the compound having the empirical formula C H O Cl converting the said compound into 4,5,6-trichloro-7 hydroxyphthalane by maintaining the said compound at, at least ambient temperature for from about 12 to about 24 hours and recovering the 4,5,6-trichloro-7-hydroXy-phthalane thereby formed.

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• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)

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Citations (4)

• 0
  • NL NL285757D patent/NL285757A/xx unknown
• 1961
  • 1961-12-08 DE DER31647A patent/DE1175250B/de active Pending
• 1962
  • 1962-11-30 US US241136A patent/US3176024A/en not_active Expired - Lifetime

Patent Citations (4)

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